Lamination adhesives

ABSTRACT

A polymer composed of 
     from 5 to 95% by weight of a mixture of at least one C 2 -C 4 -alkyl acrylate and at least one C 6 -C 12 -alkyl acrylate (monomers a), 
     from 5 to 30% by weight of ethylenically unsaturated compounds having a glass transition temperature of above 0° C. and containing no functional groups other than the ethylenically unsaturated group (monomers b), 
     from 0 to 10% by weight of ethylenically unsaturated compounds having at least one acid group or acid anhydride group (monomers c), and 
     from 0 to 60% by weight of further ethylenically unsaturated compounds (monomers d), 
     the amounts by weight being based on the emulsion polymer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to polymers composed of

from 5 to 95% by weight of a mixture of at least one C₂-C₄-alkylacrylate and at least one C₆-C₁₂-alkyl acrylate (monomers a),

from 5 to 30% by weight of ethylenically unsaturated compounds having aglass transition temperature of above 0° C. and containing no functionalgroups other than the ethylenically unsaturated group (monomers b),

from 0 to 10% by weight of ethylenically unsaturated compounds a havingat least one acid group or acid anhydride group (monomers c), and

from 0 to 60% by weight of further ethylenically unsaturated (compounds(monomers d),

the amounts by weight being based on the polymer.

The invention relates additionally to the use of the polymers asadhesives, especially as laminating adhesives, in other words forproducing laminates.

2. Description of the Background

The use of aqueous polymer dispersions as adhesives for producinglaminates, in other words as laminating adhesives, is known fromEP-A-622 434 or WO 92/12213, for example.

In practice, laminating adhesives have to meet a large number ofdifferent requirements. For example, laminating adhesives are requiredto be universally applicable; in other words, they should be equallysuitable for the bonding of different polymer films, for example ofpolyethylene (PE), oriented polypropylene (OPP), polyamide (PA) orpolyethylene terephthalate (PETP), with one another and for bondingpolymer films with paper or else, in particular, with aluminum foils ormetallized polymer films.

The laminating adhesives should have good adhesion to substrates and,after laminating, should bring about high strength of the resulting filmlaminates.

Since the film laminates are often transparent, the laminating adhesivesmust also be free from fine coagulum as well as being resistant toageing and stable to light and exhibiting little foaming.

Processing in the laminating units requires high stability to shearingand good flow properties. Moreover, aqueous systems are desirable inprinciple to avoid solvent wastes and solvent emissions.

A particular requirement is for high immediate strength of the laminatesproduced. A high immediate strength (peel strength, measured directlyafter the production of the laminate) offers the advantage that the filmlaminate can be subjected rapidly to further processing. This furtherprocessing may be the production of a triple laminate starting from thedual laminate, or further operations on the laminate (cutting, punching,folding, sealing).

The aqueous polymer dispersions known to date do not go far enoughtoward meeting the requirements placed on laminating adhesives. Inparticular, the immediate strength of the film laminates is too low.

SUMMARY OF THE INVENTION

It is an object of the present invention to remedy this situation.

We have found that this object is achieved by the polymer defined aboveand by the use thereof, or of the aqueous dispersion of the polymer, asan adhesive for producing laminates—a laminating adhesive.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The novel polymer is composed of the monomers a) to d) defined at theoutset.

The monomers a) comprise a mixture of at least one C₂-C₄-alkyl acrylateand at least one C₆-C₁₂-alkyl acrylate.

The C₂-C₄-alkyl acrylate is especially n-butyl acrylate or ethylacrylate. n-Butyl acrylate is particularly preferred.

Examples of suitable C₆-C₁₂-alkyl acrylates are n-hexyl, 2-ethylhexyl,octyl, decyl and dodecyl acrylate.

Preference is given to C₈-alkyl acrylates, especially 2-ethylhexylacrylate.

The proportion of the C₂-C₄-alkyl acrylate is preferably from 10 to 90%by weight, with particular preference from 20 to 75% by weight and, withvery particular preference, from 30 to 70% by weight, and the proportionof the C₆-C₁₂-alkyl acrylates is preferably from 90 to 10% by weight,with particular preference from 25 to 80% by weight and, with veryparticular preference, from 30 to 70% by weight, these figures by weightbeing based in each case on the overall amount of the monomers a).

Monomers a) have a glass transition temperature of below 0° C.

Monomers b) are monomers which other than the ethylenically unsaturatedgroup have no functional group, in other words no hydroxyl, acid, acidanhydride, nitro, epoxy or primary, secondary or tertiary amino group.Monomers b), or more accurately the homopolymers of the monomers b),have a glass transition temperature of above 0° C., preferably above 15°C.

The glass transition temperature of the polymer can be determined byconventional methods such as differential thermal analysis (DTA) ordifferential scanning calorimetry (DSC) (see for example ASTM 3418/82,midpoint temperature).

Examples of possible monomers b) are C_(l)-C₂₀-alkyl (meth)acrylates,vinyl esters of carboxylic acids with up to 20 carbons, vinylaromaticcompounds of up to 20 carbons, ethylenically unsaturated nitrites, andvinyl halides, provided they have the glass transition temperaturestated above.

Particularly suitable alkyl (meth)acrylates are methyl methacrylate,methyl acrylate, n-butyl methacrylate and tert-butyl acrylate.

Methyl acrylate, methyl methacrylate and butyl methacrylate arepreferred.

Examples of vinyl esters of C₁-C₂₀ carboxylic acids are vinyl laurate,stearate, propionate and acetate and Versatic acid vinyl ester.

Suitable vinylaromatic compounds are vinyltoluene, α- andp-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and,preferably, styrene. Examples of nitriles are acrylonitrile andmethacrylonitrile.

The vinyl halides are ethylenically unsaturated compounds substituted bychlorine, fluorine or bromine, preferably vinyl chloride and vinylidenechloride.

Monomers c) are, for example, ethylenically unsaturated monomers havingcarboxyl groups, such as (meth)acrylic acid, maleic acid, ethylenicallyunsaturated acid anhydrides or monoesters, such as maleic anhydride ormaleic or fumaric monoester, present in the polymer. Monomers havingsulfo or sulfonate groups are not mandatory constituents of the novelpolymer.

The further monomers, d), can be of any desired type. Preferably,mention may be made, for example, of C₁-C₁₀-hydroxyalkyl(meth)acrylates, or monomers listed under monomers b), having a glasstransition temperature of below 0° C.

The novel polymer consists preferably of

from 65 to 95 % by weight of monomers a) from 5 to 25 % by weight ofmonomers b) from 0 to 10 % by weight of monomers c) from 0 to 10 % byweight of monomers d)

and with particular preference of

from 65 to 92.5 % by weight of monomers a) from 5 to 25 % by weight ofmonomers b) from 2.5 to 10 % by weight of monomers c) from 0 to 10 % byweight of monomers d).

The glass transition temperature of the polymer can be determined by theDTA or DSC methods referred to above.

The glass transition temperature of the polymer is preferably below 60°C. and in particular is from −50 to +60° C., with particular preferencefrom −30 to +40° C. and, with very particular preference, from −30 to+20° C.

The polymer is prepared preferably by emulsion polymerization, and istherefore an emulsion polymer.

Alternatively, preparation can take place by solution polymerization andsubsequent dispersion in water.

In the case of emulsion polymerization use is made of ionic and/ornonionic emulsifiers and/or protective colloids, or stabilizers, assurface-active compounds.

A detailed description of suitable protective colloids is given inHouben-Weyl, Methoden der organischen Chemie, Volume XIV/1,Makromolekulare Stoffe, Georg-Thieme Verlag, Stuttgart, 1961, pp. 411 to420. Suitable emulsifiers include anionic, cationic and nonionicemulsifiers. Emulsifiers are preferably employed exclusively asaccompanying surface-active substances; their molecular weights, incontrast to the protective colloids, are usually below 2000 g/mol. Wheremixtures of surface-active substances are used the individual componentsmust of course be compatible; in case of doubt, this can be checked bymeans of a few preliminary experiments. It is preferred to use anionicand nonionic emulsifiers as surface-active substances. Customaryaccompanying emulsifiers are, for example, ethoxylated fatty alcohols(EO units: 3 to 50, alkyl: C₈ to C₃₆), ethoxylated mono-, di- andtrialkylphenols (EO units: 3 to 50, alkyl: C₄ to C₉), alkali metal saltsof dialkyl esters of sulfosuccinic acid, and alkali metal salts andammonium salts of alkyl sulfates (alkyl: C₈ to C₁₂), of ethoxylatedalkanols (EO units: 4 to 30, alkyl: C₁₂ to C₁₈), of ethoxylatedalkylphenols (EO units: 3 to 50, alkyl: C₄ to C₉), of alkylsulfonicacids (alkyl: C₁₂ to C₁₈) and of alkylarylsulfonic acids (alkyl: C₉ toC₁₈).

Further suitable emulsifiers are compounds of the formula II

where R⁵ and R⁶ are hydrogen or C₄-C₁₄-alkyl but are not both hydrogen,and X and Y can be alkali metal and/or ammonium ions. R⁵ and R⁶ arepreferably linear or branched alkyl of 6 to 18 carbons, and especially6, 12 or 16 carbons, or hydrogen, but are not both simultaneouslyhydrogen. X and Y are preferably sodium, potassium or ammonium ions,sodium being particularly preferred. Particularly advantageous compoundsII are those in which X and Y are sodium, R⁵ is branched alkyl of 12carbons and R⁶ is hydrogen or R⁵. In many cases use is made ofindustrial mixtures having a proportion of from 50 to 90% by weight ofthe monoalkylated product, an example being Dowfax® 2A1 (trademark ofDow Chemical Company).

Suitable emulsifiers are also given in Houben-Weyl [loc. cit.], pages192 to 208.

Examples of commercial emulsifiers are Dowfax® 2A1, Emulan® NP 50,Dextrol® OC 50, Emulgator 825, Emulgator 825 S, Emulan® OG, Texapon®NSO, Nekanil® 904 S, Lumiten® I-RA, Lumiten E 3065, Disponil FES 77,Lutensol AT 18, Steinapol VSL and Emulphor NPS 25.

The surface-active substance is usually used in amounts of from 0.1 to10% by weight, based on the monomers to be polymerized.

Examples of water-soluble initiators for the emulsion polymerization areammonium salts and alkali metal salts of peroxodisulfuric acid, forexample sodium peroxodisulfate, hydrogen peroxide or organic peroxides,for example tert-butyl hydroperoxide.

Reduction-oxidation (redox) initiator systems are particularly suitable.They consist of at least one, usually inorganic reducing agent and aninorganic or organic oxidizing agent.

The oxidation component may comprise, for example, the emulsionpolymerization initiators already mentioned above.

The reduction component comprises, for example, alkali metal salts ofsulfurous acid, for example sodium sulfite, sodium hydrogen sulfite,alkali metal salts or disulfurous acid, such as sodium disulfite,bisulfite addition compounds of aliphatic aldehydes and ketones, such asacetone bisulfite, or reducing agents such as hydroxymethanesulfinicacid and its salts, or ascorbic acid. The redox initiator systems mayalso incorporate soluble metal compounds whose metallic component isable to exist in a plurality of valence states.

Examples of common redox initiator systems are ascorbic acid/iron(II)sulfate/sodium peroxodisulfate, tert-butyl hydroperoxide/sodiumdisulfite, tert-butyl hydroperoxide/Na hydroxymethanesulfinate. Theindividual components, for example the reduction component, can also bemixtures, for example a mixture of the sodium salt ofhydroxymethanesulfinic acid and sodium disulfite.

These compounds are mostly employed in the form of aqueous solutions,the lower concentration being determined by the amount of water which isacceptable in the dispersion and the upper concentration by thesolubility of the relevant compound in water. In general theconcentration is from 0.1 to 30% by weight, preferably from 0.5 to 20%by weight and, with particular preference, from 1.0 to 10% by weight,based on the solution.

The amount of initiator is generally from 0.1 to 10% by weight,preferably from 0.5 to 5% by weight, based on the monomers to bepolymerized. It is also possible to use a plurality of differentinitiators in the emulsion polymerization.

In the course of polymerization it is possible to employ regulators, forexample in amounts of from 0 to 0.8 parts by weight per 100 parts byweight of the monomers to be polymerized. Their function is to reducethe molar mass. Suitable examples are compounds having a thiol group,such as tert-butyl mercaptan, ethylhexyl thioglycolate, mercaptoethanol,mercaptopropyl-trimethoxysilane or tert-dodecyl mercaptan. In the caseof use as an adhesive for composite-film lamination, the proportion ofsaid regulator can in particular be from 0.05 to 0.8 parts by weight,preferably from 0.1 to 0.5 parts by weight, per 100 parts by weight ofthe monomers to be polymerized. Where the intended use is as an adhesivefor high-gloss film lamination, the use of a regulator is lesspreferred. The regulators contain no polymerizable, ethylenicallyunsaturated group. They cause termination of the polymerization chainand are therefore attached terminally to the polymer chains.

The emulsion polymerization takes place generally at from 30 to 130° C.,preferably from 50 to 90° C. The polymerization medium can consisteither of water alone or of mixtures of water and water-miscibleliquids, such as methanol. Preferably, water alone is used. The emulsionpolymerization can be carried out either as a batch process or in theform of a feed process, including a staged or gradient procedure.Preference is given to the feed process, in which a portion of thepolymerization mixture is introduced as initial charge, heated to thepolymerization temperature and then partially polymerized, with theremainder of the polymerization mixture being supplied subsequently tothe polymerization zone, usually by way of a plurality of spatiallyseparate feed streams of which one or more comprise the monomers in pureor in emulsified form, these feed streams being supplied continuously,in stages or under a concentration gradient, during which thepolymerization is maintained. A seed polymer may also be included in theinitial charge in order, for example, to achieve better regulation ofparticle size.

The manner in which the initiator is added to the polymerization vesselin the course of the free-radical aqueous emulsion polymerization isfamiliar to the person of average skill in the art. It can either beincluded entirely in the initial charge to the polymerization vessel orelse added, continuously or in stages, at the rate at which it isconsumed in the course of the free-radical aqueous emulsionpolymerization. In each individual case this will depend, as familiarper se to the person of average skill in the art, both on the chemicalnature of the initiator system and on the polymerization temperature.Preferably, a portion is included in the initial charge and theremainder is supplied to the polymerization zone at the rate at which itis consumed.

In order to remove residual monomers it is common to add initiator evenafter the end of the actual emulsion polymerization, in other wordsafter a monomer conversion of at least 95%.

In the case of the feed process the individual components can be addedto the reactor from above, through the side or from below, through thereactor floor.

In the emulsion polymerization, aqueous dispersions of the polymer areobtained generally with solids contents of from 15 to 75% by weight,preferably from 40 to 75% by weight.

For a high space/time yield of the reactor, dispersions with a very highsolids content are preferred. In order to be able to achieve solidscontents >60% by weight a bimodal or polymodal particle size should beestablished, since otherwise the viscosity becomes too high and thedispersion can no longer be handled. A new particle generation can beproduced, for example, by adding seed (EP 81 083), excess amounts ofemulsifier, or miniemulsions. Another advantage associated with the lowviscosity at high solids content is the improved coating behavior athigh solids contents. One or more new generations of particles can beproduced at any desired point in time. This is guided by the targetparticle size distribution for a low viscosity.

The novel polymer can be used as an adhesive, for example apressure-sensitive adhesive. The polymer is preferably used in the formof its aqueous dispersion.

The novel dispersion is particularly suitable as a laminating adhesivefor bonding substrates of large surface area, in other words forproducing laminates.

When used as an adhesive, especially a laminating adhesive, thedispersion may comprise further conventional additives, for examplewetting agents, thickeners, protective colloids, light stabilizers orbiocides.

The novel polymer or dispersion does not require the addition oftackifying resins (tackifiers) or plasticizers nor the addition ofcrosslinkers, other reactive components or co-components in order toachieve the desired properties when used as an adhesive.

In the case of use as a laminating adhesive, the novel dispersion isapplied to the substrates of large surface area preferably in a layerthickness of from 0.1 to 20, with particular preference from 2 to 7g/m², for example by knife-coating, brushing, etc.

After a short time for evaporating the dispersion water (preferablyafter from 1 to 60 seconds) the coated substrate can be laminated with asecond substrate, it being possible for the temperature to be, forexample, from 20 to 200, preferably from 20 to 70° C. and for thepressure to be, for example, from 1 to 30, preferably from 3 to 20 N/m².

Examples of suitable substrates are polymer films, especially those ofpolyethylene, oriented polypropylene, polyamide, polyethyleneterephthalate, polyacetate, cellophane, polymer films (vapor-)coatedwith metal (e.g. aluminum) (metallized films for short) or else paper,card or metal foils, especially those of aluminum. Said foils and filmscan also be printed with printing inks, for example.

The novel polymer or dispersion can be used as an adhesive forhigh-gloss film lamination and, preferably, as an adhesive forcomposite-film lamination.

In the case of high-gloss film lamination, paper or card are bonded totransparent polymer films.

In the case of composite-film lamination, the abovementioned substrates(but not paper or card) can be bonded to one another. Different polymerfilms can be bonded to one another, for example. Particularly goodresults are obtained in connection with the bonding of polymer films tometal foils, for example aluminum, or metallized films.

An advantage of the invention is that a very wide range of substratescan be bonded to one another, ie. laminated, with the novel dispersionhaving good adhesion to the substrates and bringing about a highstrength of the bonded composite. In particular, the immediate strengthis very high, thereby enabling further processing to be carried outrapidly, for example.

EXAMPLES

I Preparing Emulsion Polymers

The polymers were prepared in accordance with the following generalprocedure:

The initial charge (composition see Table 1) was heated to 85° C.(internal temperature). Then feed stream 1 and feed stream 2 were begun.

Feed stream 2 consisted of 3.0 g of sodium peroxodisulfate (initiator)in 39.9 g of water.

Feed stream 1 contained the emulsified monomer mixture. The compositionof feed stream 2 is likewise indicated in Table 1.

Feed stream 1 was metered in over 3 h. 20% of feed stream 2 was addedover 10 minutes and the remainder over 2 h 50 min (procedure 1) or over3 h 20 min (procedure 2). After the end of the feed streams,polymerization was continued at 85° C. for half an hour.

The composition of the resulting emulsion polymers 1 to 13 is shown inTable 2.

TABLE 1 Composition of the initial charge and of feed stream 1 Initialcharge Feed stream 1 Styrene Styrene SLS IRA DOW Ar. seed seed 15% in60% in 45% in 15% in t-DMC DVB H₂O 10% in 33% in H₂O water water waterwater 100% 100% Monomers Proce- [g] water [g] water [g] [g] [g] [g] [g][g] [g] [g] 100% [g] dure 1 312 5 450 13.3 6.7 14.4 2 1 1000 1 2 312 5449.2 13.3 6.7 14.4 2 1000 1 3 312 5 448.2 13.3 6.7 14.4 2.5 1000 1 4317.5 5 447.7 13.3 6.7 14.4 1.8 1000 1 5 317.5 5 447.8 13.3 6.7 14.4 21000 1 6 317.5 5 447.7 13.3 6.7 14.4 1.8 1000 1 7 317.5 5 447.7 13.3 6.714.4 1.8 1000 1 8 317.5 5 418.6 6.7 14.4 53.3 1.8 1000 1 9 317.5 5 447.413.3 6.7 14.4 1.8 1000 1 10 317.5 5 447.7 13.3 6.7 14.4 1.8 1000 1 11317.5 5 447.7 13.3 6.7 14.4 0.22 1000 1 12 317.5 5 447.7 13.3 6.7 14.40.22 1000 1 13 317.5 5 447.7 13.3 6.7 14.4 0.22 1000 1 AbbreviationsSLS: sodium lauryl sulfate IRA: Lumiten IRA Dow: Dowfax 2A1 Ar.:arylsulfonate t-DMC: tert-dodecyl mercaptan DVB: divinylbenzene

TABLE 2 Composition of the emulsion polymers in % by weight AA IA GMAHEA BA MA MMA EHA S 1 3 56  5 8 28 2 3 0.5 0.5 51 10 7 28 3 3 56 8 28  54 3 56 10  28  3 5 3 51 33 13 6 3 46 38 13 7 3 43 41 13 8 3 46 38 13 9 346 13 38 10  3 51 33 13 11  3 51 33 13 12* 3 — 84 13 13* 3 84 — 13Abbreviations AA: acrylic acid IA: itaconic acid GMA: glycidylmethacrylate HEA: 2-hydroxyethyl acrylate BA: n-butyl acrylate MA:methyl acrylate MMA: methyl methacrylate EHA: ethylhexyl acrylate S:styrene *for comparison

II Performance Tests

A) Composite Films

Producing the Composite Films and Determining the Peel Strength

The dispersions of the emulsion polymers were knife-coated with adry-film thickness of 2-3 g/m² on various films which had been heated to50° C. (polyethylene terephthalate: PETP; polyamide; PA; polypropylene(corona-pretreated): PP, aluminum: Alu), and after 20 seconds werelaminated with a corona-pretreated polyethylene film (PE). The resultingfilm laminates were then stored for 1 day at room temperature understandard climatic conditions and then cut into strips 15 mm wide. Thesestrips were then peeled at an angle of 180° C. and at a rate of 100m/min at 23° C. The peel strength found for the 15 mm wide strips, in N,was measured. The results are given in Table 3.

TABLE 3 Peel strengths in N/15 mm metall. Polymer PETP/PE PA/PE PP/BEAlu/PE PETP/Alu PETP/PE* 1 3.1 2.4 2.3 3.3 3.5 2 2.8 2.5 2.2 3.2 3.3 3.33 2.7 3.0 2.8 4.5 4.0 3.2 4 3.8 3.7 3.0 4.5 5.1 3.1 5 3.1 3.0 2.4 4.74.0 2.9 6 2.3 3.2 2.4 3.0 3.4 2.5 7 2.8 3.0 2.7 3.7 3.7 2.3 8 2.9 3.02.5 3.8 3.3 3.0 9 3.2 3.2 2.3 3.8 3.0 2.7 10  2.5 2.6 2.0 3.7 2.2 1.411  2.9 3.3 2.7 3.8 3.6 3.1 12  0.5 0.6 0.7 1.3 1.3 0.6 13  2.2 2.5 2.13.1 3.8 1.8 *PETP film vapor-coated with metal

Determining the Immediate Strength

Another advantage of the novel dispersions is regarded as being the highimmediate strength of the composites produced. This high immediatestrength (peel strength measured directly after production of thecomposite) offers the advantage that the film laminate can be subjectedrapidly to further processing. This further processing can be theproduction of a triple laminate starting from dual laminate, or furtheroperations on the laminate (cutting, punching, folding, sealing). Thecomparative example is a 2-component system comprising an acrylicpolymer dispersion (Acronal® DS 3480) including an isocyanatecrosslinker.

Immediate Strength

Polymer PETP/PE PA/PE PP/PE ALU/PE PETP/ALU 3 1.5 2.0 2.0 3.0 2.4Acronal DS 0.2 0.4 0.3 1.4 0.7 3480 X

B) High-gloss Films

Preparing Polymer dispersions 14 and 15

Polymer 14

Initial charge: 312.0 g of water 0.05% 5.0 g of styrene seed  10.0%strength Feed stream 1: 449.5 g of water 0.20% 13.3 g of Steinapol NLS 15.0% strength 0.40% 8.0 g of Lumiten IRA  50.0% strength 0.65% 14.4 gof Dowfax 2A1  45.0% strength 0.10% 4.0 g of NaOH  25.0% strength 3.00%30.0 g of acrylic acid 100.0% strength 56.00%  560.0 g of n-butylacrylate 100.0% strength 5.00% 50.0 g of styrene 100.0% strength 8.00%80.0 g of methyl methacrylate 100.0% strength 28.00%  280.0 g of2-ethylhexyl acrylate 100.0% strength Feed stream 2: 0.30% 3.0 g ofsodium peroxodisulfate 100.0% strength 39.9 g of water

Procedure:

Heat initial charge to 85° C.

Begin feed streams simultaneously at 85° C.

Feed time:

feed stream 1 over 3 h

feed stream 2: 20% over 10 minutes, remainder over 2 h 50 min

After the end of addition, continue polymerization at internal temp. of85° C. for 0.5 h

Adjust pH to 7-8 using NaOH

Polymer 15

Initial charge: 312.0 g of water 0.05% 5.0 g of styrene seed 10.0%strength Feed stream 1: 451.6 g of water 0.20% 13.3 g of Steinapol NLS 15.0% strength 0.40% 8.0 g of Lumiten IRA  50.0% strength 0.65% 14.4 gof Dowfax 2A1  45.0% strength 3.00% 30.0 g of acrylic acid 100.0%strength 56.00%  560.0 g of n-butyl acrylate 100.0% strength 5.00% 50.0g of styrene 100.0% strength 8.00% 80.0 g of methyl methacrylate 100.0%strength 28.00%  280.0 g of 2-ethylhexyl acrylate 100.0% strength Feedstream 2: 0.30% 3.0 g of sodium peroxodisulfate 100.0% strength 39.9 gof water

Procedure:

Heat initial charge to 85° C.

Begin feed streams simultaneously at 85° C.

Feed time:

feed stream 1 over 3 h

feed stream 2: 20% over 10 minutes, remainder over 2 h 50 min

After the end of addition, continue polymerization at internal temp. of85° C. for 0.5 h

Adjust pH to 7-8 using NaOH

High-gloss Film Lamination with Card and Polypropylene(Corona-pretreated)

The pretreated side of the polypropylene film was coated with adhesive.After drying in cold air, the card was placed on and the assembly wasrolled down using a laboratory laminating roller. After being cut tosize, the laminates were compressed in a roller press.

The adhesion was tested by peeling the film from the card at an angle ofabout 180 degrees.

Assessment:

1=Full tearing of paper or paint

2=Partial tearing of paper or paint

3=Good adhesion, with adhesive fracture of card or film (AC, AF)

4=Poor adhesion with AC or AF

5=No adhesion to card or film

In order to determine the groove stability, the laminated samples weregiven a groove 24 hours after the above production.

Evaluation of the Groove

1=Groove is entirely satisfactory

2=Groove has opened slightly only at isolated points

3=Groove has opened noticeably at certain points

4=Groove is completely open

The results are summarized in Table 4.

TABLE 4 Adhesion Groove condition after after after after after afterPolymer 1 day 1 week 6 weeks 1 day 1 week 6 weeks 14 3 2-3 2-3 1 1 1 152 2 2 1 1 1

We claim:
 1. A laminate of paper or card, comprising thereon atransparent polymer film bonded thereto with an adhesive polymer, saidadhesive polymer being produced from a monomer mixture, comprising: a)from 5-95% by weight of a mixture with at least one C₂-C₄-alkyl acrylateand at least one C₆-C₁₂-alkyl acrylate (monomers a); b) from 5-30% byweight of ethylenically unsaturated compounds having a glass transitiontemperature of above 0° C. and containing no functional groups otherthan the ethylenically unsaturated group (monomers b); c) from 0-10% byweight of ethylenically unsaturated compounds having at least one acidgroup or acid anhydride group (monomers c); and d) from 0-60% by weightof further ethylenically unsaturated compounds (monomers d); the weightpercentages being based on the adhesive polymer, or of an aqueousdispersion of the adhesive polymer.
 2. The laminate of claim 1, whereinfor said adhesive polymer, monomers a) comprise from 10-90% by weight ofC₂-C₄-alkyl acrylates and from 90-10% by weight of C₆-C₁₂-alkylacrylates.
 3. The laminate of claim 1, wherein said adhesive polymer isproduced from: 65-95% by weight of monomers a); from 5-25% by weight ofmonomers b); from 0-10% by weight of monomers c); and from 0-10% byweight of monomers d).
 4. The laminate of claim 1, wherein said adhesivepolymer is produced from: 65-92.5% by weight of monomers a); from 5-25%by weight of monomers b); from 2.5-10% by weight of monomers c); andfrom 0-10% by weight of monomers d).
 5. The laminate of claim 1, whereinsaid adhesive polymer is prepared by emulsion polymerization of themonomers a)-d) in the presence of from 0.05 to 0.8 parts by weight of aregulator per 100 parts by weight of the monomers a)-d) to bepolymerized.
 6. The laminate of claim 1, wherein said monomers a)comprise n-butyl acrylate or ethyl acrylate as said C₂-C₄-alkylacrylate, and n-hexyl-, 2-ethylhexyl-, octyl-, decyl- or dodecylacrylate as said C₆-C₁₂-acrylate.
 7. The laminate of claim 6, whereinsaid C₂-C₄-alkyl acrylate is n-butyl acrylate, and said C₆-C₁₂-alkylacrylate is 2-ethylhexyl acrylate.
 8. The laminate of claim 1, whereinsaid monomers a) have a glass transition temperature of below 0° C. 9.The laminate of claim 1, wherein said monomers b) have a glasstransition temperature of above 0° C.
 10. The laminate of claim 9,wherein said monomers b) have a glass transition temperature of above15° C.
 11. The laminate of claim 1, wherein said monomers b) compriseC₁-C₂₀-alkyl (meth)acrylates, vinyl esters of carboxylic acids with upto 20 carbons, vinyl aromatic carbons of up to 20 carbons, ethylenicallyunsaturated nitriles or vinyl halides having a glass transitiontemperature of above 0° C.
 12. The laminate of claim 11, wherein saidmonomers b) comprise methyl acrylate, methyl methacrylate, butylmethacrylate, vinyl laurate, vinyl stearate, vinyl propionate, vinylacetate, versatic acid vinyl ester, vinyl toluene, α- andp-methylstyrene, (α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene,styrene, acrylonitrile, methacrylonitrile, vinyl chloride or vinylidenechloride.
 13. The laminate of claim 1, wherein said monomers c) comprise(meth)acrylic acid, maleic acid, maleic anhydride, maleic monoester orfumaric monoester.
 14. The laminate of claim 1, wherein said monomers d)have a glass transition temperature of below 0° C.
 15. The laminate ofclaim 1, wherein said monomers d) comprise C₁-C₁₀-hydroxyalkyl(meth)acrylates or are as defined for monomers b).
 16. The laminate ofclaim 1, wherein said adhesive polymer has a glass transitiontemperature of from −50 to +60° C.
 17. The laminate of claim 16, whereinsaid adhesive polymer has a glass transition temperature of from −30 to+40° C.
 18. The laminate of claim 17, wherein said adhesive polymer hasa glass transition temperature of from −30 to +20° C.
 19. The laminateof claim 1, wherein said adhesive polymer does not contain tackifiers,plasticizers or crosslinker.
 20. The laminate of claim 1, wherein saidtransparent polymer film is polypropylene.
 21. The laminate of claim 20,wherein said polypropylene is corona-pretreated.
 22. The laminate ofclaim 1, which is glossy.
 23. The laminate of claim 1, wherein theadhesive polymer contains neither sulfo nor sulfonate groups.
 24. Thelaminate of claim 1, which is of paper.
 25. The laminate of claim 1,which is of card.